Wong Willard, Brogi Edi, Reis-Filho Jorge S, Plitas George, Robson Mark, Norton Larry, Morrow Monica, Wen Hannah Y
Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
NPJ Breast Cancer. 2021 Jul 22;7(1):96. doi: 10.1038/s41523-021-00302-z.
Metaplastic breast carcinoma (MpBC) is a rare special histologic subtype of breast carcinoma characterized by the presence of squamous and/or mesenchymal differentiation. Most MpBCs are of triple-negative phenotype and neoadjuvant chemotherapy (NAC) is frequently utilized in patients with MpBC. The aim of this study was to evaluate response to NAC in a retrospective cohort of MpBCs. We identified 44 patients with MpBC treated with NAC at our center between 2002 and 2018. Median age was 48 years, 86% were clinical stage II-III, and 36% were clinically node-positive. Most (80%) MpBCs were triple-negative or low (1-10%) hormonal receptor positive and HER2 negative on pre-NAC biopsy. While on NAC, 49% showed no clinical response or clinico-radiological progression. Matrix-producing subtype was associated with clinico-radiological response (p = 0.0036). Post NAC, two patients initially ineligible for breast-conserving surgery (BCS) were downstaged to be eligible for BCS, whereas three patients potentially eligible for BCS before treatment became ineligible due to disease progression. Only one (2%) patient had a pathologic complete response (pCR). Among the 16 patients presenting with biopsy-proven clinical node-positive disease, 3 (19%) had nodal pCR. Axillary lymph node dissection was avoided in 3 (19%) patients who had successful axillary downstaging. Residual cancer burden (RCB) was assessed in 22 patients and was significantly associated with disease-free survival and overall survival. We observed a poor response or even disease progression on NAC among patients with MpBC, suggesting that NAC should be reserved for patients with inoperable MpBC.
化生性乳腺癌（MpBC）是一种罕见的特殊组织学类型的乳腺癌，其特征是存在鳞状和/或间充质分化。大多数MpBC为三阴性表型，新辅助化疗（NAC）常用于MpBC患者。本研究的目的是评估MpBC回顾性队列中对NAC的反应。我们确定了2002年至2018年间在我们中心接受NAC治疗的44例MpBC患者。中位年龄为48岁，86%为临床II-III期，36%临床淋巴结阳性。大多数（80%）MpBC在NAC前活检时为三阴性或低（1-10%）激素受体阳性且HER2阴性。在接受NAC治疗期间，49%无临床反应或临床放射学进展。产生基质的亚型与临床放射学反应相关（p = 0.0036）。NAC后，两名最初不符合保乳手术（BCS）条件的患者分期降低，符合BCS条件，而三名治疗前可能符合BCS条件的患者因疾病进展而不符合条件。只有一名（2%）患者达到病理完全缓解（pCR）。在16例活检证实临床淋巴结阳性疾病的患者中，3例（19%）达到淋巴结pCR。3例（19%）成功实现腋窝降期的患者避免了腋窝淋巴结清扫。对22例患者评估了残余癌负担（RCB），其与无病生存期和总生存期显著相关。我们观察到MpBC患者对NAC反应不佳甚至疾病进展，这表明NAC应仅用于无法手术的MpBC患者。
